Why are you only running 4 days a week?
4 running days and 3 lifting days is actually my exact schedule right now, and also the schedule of many people just looking to get into shape or be well rounded.
So you first need to know what your goal is. If you want to be healthy, fit, and a relatively well-rounded athlete I would suggest this:
Sun: Long run
Mon: Bodyweight lifts and plyos*
Tue: Short Sprints w/run
Wed: Circuit Training*
Thu: Easy run
Fri: Lift for max strength*
Sat: Easy run or longer steady interals (mile on/mile off)
*Bodyweight lifts/plyos:
Pushups: 3-5 sets to failure
Pullups: 3-5 sets to failure
Planks: 3-5 sets of 30-60s
Box Jump or Split Box Jump: 3-5 sets of 5-10
Leg Crank: 1-3 sets of 12-25 of each in a row: squat, alt. lunge, split jump, jump squat
*Circuit Training:
DB, BB or Machine Circuit of the following movement patterns: Horizontal Pressing, Horizontal Pulling, Vertical Pressing, Vertical Pulling, Quad Dominant, Hip Dominant, Bicep, Tricep, Ab, Back
3-5 rounds for time, 10-15 reps
*Lift for Max Strength:
Look up Wendler's 5/3/1 program do something similar. I like the following....
For Squat, Bench, Deadlift in that order:
Week 1-3: warmup and ramp up to a max set of 5
Week 4-6: warmup and ramp up to a max set of 3
Week 7-9: warmup and ramp up to a max set of 1
Switch Deadlift and Squat then repeat the 9 week program.
That's it, no other lifts this day.
Anyway...this is one way to do it...
Alan